Spin Echo and Interference in Synchrotrons (open access)

Spin Echo and Interference in Synchrotrons

Spin dynamics in crossing a single depolarization resonance is a well-studied subject. One well-known example is that of Froissart and Stora in 1960. More is needed to complete the understanding, particularly of the transient effects, when crossing a single resonance, but question arises what happens if we cross two resonances or cross a single resonance twice. When a resonance is crossed twice, the particle's spin dynamics encounters two additional phenomena. First, the two crossings will interfere with each other, leading to an interference effect. Second, there will be a spin echo effect. We discuss these two effects in this report. Two proposals to test these effects experimentally are made at the end.
Date: November 30, 2006
Creator: Chao, Alex
Object Type: Article
System: The UNT Digital Library
Cost-Effective Reciprocating Engine Emissions Control and Monitoring for E & P Field and Gathering Engines (open access)

Cost-Effective Reciprocating Engine Emissions Control and Monitoring for E & P Field and Gathering Engines

Continuing work in controlled testing uses a one cylinder Ajax DP-115 (a 13.25 in bore x 16 in stroke, 360 rpm engine) to assess a sequential analysis and evaluation of a series of engine upgrades. As with most of the engines used in the natural gas industry, the Ajax engine is a mature engine with widespread usage throughout the gas gathering industry. The end point is an assessment of these technologies that assigns a cost per unit reduction in NO{sub X} emissions. Technologies including one pre-combustion chamber, in-cylinder sensors, the means to adjust the air-to-fuel ratio, and modification of the air filter housing have been evaluated in previous reports. Current work tests non-production, prototype, mid-pressure fuel valves and begins analysis of these tests. This analysis reveals questions which must be answered before coming to any firm conclusions about the use of the180 psig fuel valve. The research team plans to continue with the remaining pre-combustion chamber tests in the coming quarter. By using the Ajax DP-115 these tests are completed in a low-cost and efficient manner. The various technologies can be quickly exchanged with different hardware, and it is inexpensive to run the engine. Progress in moving toward field testing …
Date: September 30, 2006
Creator: Chapman, Kirby S. & Nuss-Warren, Sarah R.
Object Type: Report
System: The UNT Digital Library
Partial Support for U.S. Participants in the International Marine Biotechnology Conference 2005, in Newfoundland, Canada, June 7-12, 2005 (open access)

Partial Support for U.S. Participants in the International Marine Biotechnology Conference 2005, in Newfoundland, Canada, June 7-12, 2005

This proposal requests inter-agency support for U.S. scientists to attend the IMBC2005. This meeting is the premier international Marine Biotechnology meeting and emphasizes the use of molecular approaches in studying the protection and enhancement of global marine resources. The scientific programs of IMBC2005 include Marine Microbiology, Genomics and Proteomics, Extremophiles, Bioremediation, Cell and Molecular Biology, Bioactives, Transgenics, Aquaculture, Seafood Safety, and Biodiversity. For more information, please refer to http://www.imbc2005.org/welcome_e.html. The objectives of this proposal are to: 1. Facilitate attendance by a broad range of U.S. scientists, technologists, and students at the MBC2005 2. Ensure that U.S. scientists are exposed to the latest global advances in Marine Biotechnology 3. Encourage collaboration between U.S. and other scientists in the important and rapidly developing field of Marine Biotechnology.
Date: September 30, 2006
Creator: Chen, Feng
Object Type: Report
System: The UNT Digital Library
Heterogeneous Shallow-Shelf Carbonate Buildups in the Paradox Basin, Utah and Colorado: Targets for Increased Oil Production and Reserves Using Horizontal Drilling Techniques (open access)
Agricultural Disaster Assistance (open access)

Agricultural Disaster Assistance

This report discusses the ongoing major USDA disaster programs designed to help crop producers recover from the financial effects of natural disasters — federal crop insurance, noninsured assistance program (NAP) payments, and emergency disaster loans.
Date: June 30, 2006
Creator: Chite, Ralph M.
Object Type: Report
System: The UNT Digital Library
Functionally Graded Cathodes for Solid Oxide Fuel Cells (open access)

Functionally Graded Cathodes for Solid Oxide Fuel Cells

This DOE SECA project focused on both experimental and theoretical understanding of oxygen reduction processes in a porous mixed-conducting cathode in a solid oxide fuel cell (SOFC). Elucidation of the detailed oxygen reduction mechanism, especially the rate-limiting step(s), is critical to the development of low-temperature SOFCs (400 C to 700 C) and to cost reduction since much less expensive materials may be used for cell components. However, cell performance at low temperatures is limited primarily by the interfacial polarization resistances, specifically by those associated with oxygen reduction at the cathode, including transport of oxygen gas through the porous cathode, the adsorption of oxygen onto the cathode surface, the reduction and dissociation of the oxygen molecule (O{sub 2}) into the oxygen ion (O{sup 2-}), and the incorporation of the oxygen ion into the electrolyte. In order to most effectively enhance the performance of the cathode at low temperatures, we must understand the mechanism and kinetics of the elementary processes at the interfaces. Under the support of this DOE SECA project, our accomplishments included: (1) Experimental determination of the rate-limiting step in the oxygen reduction mechanism at the cathode using in situ FTIR and Raman spectroscopy, including surface- and tip-enhanced Raman spectroscopy …
Date: September 30, 2006
Creator: Choi, YongMan & Liu, Meilin
Object Type: Report
System: The UNT Digital Library
Operational Challenges in Gas-To-Liquid (GTL) Transportation Through Trans Alaska Pipeline System (TAPS) (open access)

Operational Challenges in Gas-To-Liquid (GTL) Transportation Through Trans Alaska Pipeline System (TAPS)

Oil production from Alaskan North Slope oil fields has steadily declined. In the near future, ANS crude oil production will decline to such a level (200,000 to 400,000 bbl/day) that maintaining economic operation of the Trans-Alaska Pipeline System (TAPS) will require pumping alternative products through the system. Heavy oil deposits in the West Sak and Ugnu formations are a potential resource, although transporting these products involves addressing important sedimentation issues. One possibility is the use of Gas-to-Liquid (GTL) technology. Estimated recoverable gas reserves of 38 trillion cubic feet (TCF) on the North Slope of Alaska can be converted to liquid with GTL technology and combined with the heavy oils for a product suitable for pipeline transport. Issues that could affect transport of this such products through TAPS include pumpability of GTL and crude oil blends, cold restart of the pipeline following a prolonged winter shutdown, and solids deposition inside the pipeline. This study examined several key fluid properties of GTL, crude oil and four selected blends under TAPS operating conditions. Key measurements included Reid Vapor Pressure, density and viscosity, PVT properties, and solids deposition. Results showed that gel strength is not a significant factor for the ratios of GTL-crude oil …
Date: June 30, 2006
Creator: Chukwu, Godwin A.; Khataniar, Santanu; Patil, Shirish & Dandekar, Abhijit
Object Type: Report
System: The UNT Digital Library
Evaluating the Potential Impact of Transmission Constraints on the Operation of a Competitive Electricity Market in Illinois. (open access)

Evaluating the Potential Impact of Transmission Constraints on the Operation of a Competitive Electricity Market in Illinois.

Despite the current adequacy of the generation and transmission system in Illinois, there is concern that the uncertainties of electricity restructuring warrant a more detailed analysis to determine if there might be pitfalls that have not been identified under current conditions. The problems experienced elsewhere in the country emphasize the need for an evaluation of how Illinois might fare under a restructured electricity market. The Illinois Commerce Commission (ICC) commissioned this study to be undertaken as a joint effort by the University of Illinois at Urbana-Champaign and Argonne National Laboratory to evaluate the Illinois situation in the 2007 period when restructuring is scheduled to be fully implemented in the State. The purpose of this study is to make an initial determination if the transmission system in Illinois and the surrounding region would be able to support a competitive electricity market, would allow for effective competition to keep prices in check, and would allow for new market participants to effectively compete for market share. The study seeks to identify conditions that could reasonably be expected to occur that would enable a company to exercise market power in one or more portions of the State and thereby create undue pressure on the …
Date: April 30, 2006
Creator: Cirillo, R.; Thimmapuram, P.; Veselka, T.; Koritarov, V.; Conzelmann, G.; Macal, C. et al.
Object Type: Report
System: The UNT Digital Library
DOWNHOLE VIBRATION MONITORING & CONTROL SYSTEM (open access)

DOWNHOLE VIBRATION MONITORING & CONTROL SYSTEM

The objective of this program is to develop a system to both monitor the vibration of a bottomhole assembly, and to adjust the properties of an active damper in response to these measured vibrations. Phase I of this program, which entailed modeling and design of the necessary subsystems and design, manufacture and test of a full laboratory prototype, was completed on May 31, 2004. The principal objectives of Phase II were: more extensive laboratory testing, including the evaluation of different feedback algorithms for control of the damper; design and manufacture of a field prototype system; and, testing of the field prototype in drilling laboratories and test wells. Phase II concluded on January 31, 2006, and the final report was issued. Work on Phase III of the project began during the previous quarter. Efforts this quarter have focused on the manufacture of the prototype and precommercial parts, field test planning and commercialization. The current extreme lead times quoted by oilfield machine shops for collar components, will delay the deployment of the field prototypes. The delivery date for five critical parts from one supplier has slipped to late November, which will preclude deployment for a field test before late December or early …
Date: September 30, 2006
Creator: Cobern, Martin E.
Object Type: Report
System: The UNT Digital Library
Downhole Vibration Monitoring & Control System (open access)

Downhole Vibration Monitoring & Control System

None
Date: June 30, 2006
Creator: Cobern, Martin E.
Object Type: Report
System: The UNT Digital Library
New Optimal Sensor Suite for Ultrahigh Temperature Fossil Fuel Applications (open access)

New Optimal Sensor Suite for Ultrahigh Temperature Fossil Fuel Applications

Accomplishments during Phase II of a program to develop and demonstrate photonic sensor technology for the instrumentation of advanced powerplants are described. The goal of this project is the research and development of advanced, robust photonic sensors based on improved sapphire optical waveguides, and the identification and demonstration of applications of the new sensors in advanced fossil fuel power plants, where the new technology will contribute to improvements in process control and monitoring. During this program work period, major progress has been experienced in the development of the sensor hardware, and the planning of the system installation and operation. The major focus of the next work period will be the installation of sensors in the Hamilton, Ohio power plant, and demonstration of high-temperature strain gages during mechanical testing of SOFC components.
Date: September 30, 2006
Creator: Coggin, John; Ivasauskas, Jonas; May, Russell G.; Miller, Michael B. & Wilson, Rena
Object Type: Report
System: The UNT Digital Library
Supplemental Release Limits for the Directed Reuse of Steel in Road Barriers and Lead in Shielding Products by the Department of Energy (open access)

Supplemental Release Limits for the Directed Reuse of Steel in Road Barriers and Lead in Shielding Products by the Department of Energy

None
Date: April 30, 2006
Creator: Coleman, R.L. & Bogard, J.S.
Object Type: Report
System: The UNT Digital Library
Hydraulic Characteristics of the Lower Snake River During Periods of Juvenile Fall Chinook Migration (open access)

Hydraulic Characteristics of the Lower Snake River During Periods of Juvenile Fall Chinook Migration

This report documents a four-year study to assess hydraulic conditions in the lower Snake River. The work was conducted for the Bonneville Power Administration, U.S. Department of Energy, by the Pacific Northwest National Laboratory. Cold water released from the Dworshak Reservoir hypolimnion during mid- to late-summer months cools the Clearwater River far below equilibrium temperature. The volume of released cold water augments the Clearwater River, and the combined total discharge is on the order of the Snake River discharge when the two rivers meet at their confluence near the upstream edge of Lower Granite Reservoir. With typical temperature differences between the Clearwater and Snake rivers of 10°C or more during July and August, the density difference between the two rivers during summer flow augmentation periods is sufficient to stratify Lower Granite Reservoir as well as the other three reservoirs downstream. Because cooling of the river is desirable for migrating juvenile fall Chinook salmon (Oncorhynchus tshawytscha) during this same time period, the amount of mixing and cold water entrained into Lower Granite Reservoir’s epilimnion at the Clearwater/Snake River confluence is of key biological importance to juvenile fall Chinook salmon. Data collected during this project indicates the three reservoirs downstream of Lower …
Date: January 30, 2006
Creator: Cook, Chris B.; Dibrani, Berhon; Richmond, Marshall C.; Bleich, Matthew D.; Titzler, P. Scott & Fu, Tao
Object Type: Report
System: The UNT Digital Library
Acoustic Doppler Current Profiler Measurements in the Tailrace at John Day Dam (open access)

Acoustic Doppler Current Profiler Measurements in the Tailrace at John Day Dam

Acoustic Doppler current profilers (ADCPs) were used to measure water velocities in the tailrace at John Day Dam over a two-week period in February 2005. Data were collected by the Pacific Northwest National Laboratory for the Hydraulic Design Section, Portland District, U.S. Army Corps of Engineers (USACE). The objective of this project was therefore to collect field measurements of water velocities in the near-field draft tube exit zone as well as the far-field tailrace to be used for improving these models. Field data were collected during the project using five separate ADCPs. Mobile ADCP data were collected using two ADCPs mounted on two separate boats. Data were collected by either holding the boat on-station at pre-defined locations for approximately 10 minutes or in moving transect mode when the boat would move over large distances during the data collection. Results from the mobile ADCP survey indicated a complex hydrodynamic flow field in the tailrace downstream of John Day Dam. A large gyre was noted between the skeleton section of the powerhouse and non-spilling portion of the spillway. Downstream of the spillway, the spillway flow is constrained against the navigation lock guide wall, and large velocities were noted in this region. Downstream …
Date: January 30, 2006
Creator: Cook, Chris B.; Dibrani, Berhon; Serkowski, John A.; Richmond, Marshall C.; Titzler, P. Scott & Dennis, Gary W.
Object Type: Report
System: The UNT Digital Library
AIDS in Africa (open access)

AIDS in Africa

Sub-Saharan Africa has been far more severely affected by AIDS than any other part of the world. The United Nations reports that 25.8 million adults and children are infected with the HIV virus in the region, which has about 11.15% of the world's population but more than 64% of the worldwide total of infected people. This report discusses this issue in detail, including the cause of the African AIDS epidemic, the social and economic consequences, response and treatment, and U.S. policy.
Date: January 30, 2006
Creator: Cook, Nicolas
Object Type: Report
System: The UNT Digital Library
Liberia's Post-War Recovery: Key Issues and Developments (open access)

Liberia's Post-War Recovery: Key Issues and Developments

This report covers recent developments in Liberia, a small, poor West African country which began a post-conflict transition process to achieve enduring peace, socio-economic reconstruction and democratic governance.
Date: January 30, 2006
Creator: Cook, Nicolas
Object Type: Report
System: The UNT Digital Library
Analysis of Soluble Re Concentrations in Refractory from Bulk Vitrification Full-Scale Test 38B (open access)

Analysis of Soluble Re Concentrations in Refractory from Bulk Vitrification Full-Scale Test 38B

The capacity of the waste treatment plant (WTP) being built at the Hanford Site is not sufficient to process all of the tank waste accumulated from more than 40 years of nuclear materials production. Bulk vitrification can accelerate tank waste treatment by providing some supplemental low-activity waste (LAW) treatment capacity. Bulk vitrification combines LAW and glass-forming chemicals in a large metal container and melts the contents using electrical resistance heating. A castable refractory block (CRB) is used along with sand to insulate the container from the heat generated while melting the contents into a glass waste form. This report describes engineering-scale (ES) and full-scale (FS) tests that have been conducted. Several ES tests showed that a small fraction of soluble Tc moves in the CRB and results in a groundwater peak different than WTP glass. The total soluble Tc-99 fraction in the FS CRB is expected to be different than that determined in the ES tests, but until FS test results are available, the best-estimate soluble Tc-99 fraction from the ES tests has been used as a conservative estimate. The first FS test results are from cold simulant tests that have been spiked with Re. An estimated scale-up factor extrapolates …
Date: June 30, 2006
Creator: Cooley, Scott K.; Pierce, Eric M.; Bagaasen, Larry M. & Schweiger, Michael J.
Object Type: Report
System: The UNT Digital Library
Generalized System of Preferences (open access)

Generalized System of Preferences

This report discusses the Generalized System of Preferences (GSP), which provides preferential tariff treatment to certain products that are imported from designated developing countries. The primary purpose of the program, which the United States and other industrial countries initiated in the 1970s, is to promote economic growth in developing countries and countries in transition by stimulating their exports. The program was last reauthorized through December 31, 2006, by the 107th Congress in section 4101 of the Trade Act of 2002 (P.L. 107-210).
Date: March 30, 2006
Creator: Cooper, William H.
Object Type: Report
System: The UNT Digital Library
U.S.-Japan Economic Relations: Significance, Prospects, and Policy Options (open access)

U.S.-Japan Economic Relations: Significance, Prospects, and Policy Options

None
Date: August 30, 2006
Creator: Cooper, William H.
Object Type: Report
System: The UNT Digital Library
Hydrogen Generation from Biomass-Derived Surgar Alcohols via the Aqueous-Phase Carbohydrate Reforming (ACR) Process (open access)

Hydrogen Generation from Biomass-Derived Surgar Alcohols via the Aqueous-Phase Carbohydrate Reforming (ACR) Process

This project involved the investigation and development of catalysts and reactor systems that will be cost-effective to generate hydrogen from potential sorbitol streams. The intention was to identify the required catalysts and reactors systems as well as the design, construction, and operation of a 300 grams per hour hydrogen system. Virent was able to accomplish this objective with a system that generates 2.2 kgs an hour of gas containing both hydrogen and alkanes that relied directly on the work performed under this grant. This system, funded in part by the local Madison utility, Madison, Gas & Electric (MGE), is described further in the report. The design and development of this system should provide the necessary scale-up information for the generation of hydrogen from corn-derived sorbitol.
Date: June 30, 2006
Creator: Cortright, Randy
Object Type: Report
System: The UNT Digital Library
Statutory Interpretation: General Principles and Recent Trends (open access)

Statutory Interpretation: General Principles and Recent Trends

None
Date: March 30, 2006
Creator: Costello, George
Object Type: Report
System: The UNT Digital Library
TOXICITY CHARACTERISTIC LEACHING PROCEDURE APPLIED TO RADIOACTIVE SALTSTONE CONTAINING TETRAPHENYLBORATE: DEVELOPMENT OF A MODIFIED ZERO-HEADSPACE EXTRACTOR (open access)

TOXICITY CHARACTERISTIC LEACHING PROCEDURE APPLIED TO RADIOACTIVE SALTSTONE CONTAINING TETRAPHENYLBORATE: DEVELOPMENT OF A MODIFIED ZERO-HEADSPACE EXTRACTOR

In order to assess the effect of extended curing times at elevated temperatures on saltstone containing Tank 48H waste, saltstone samples prepared as a part of a separate study were analyzed for benzene using a modification of the United States Environmental Protection Agency (USEPA) method 1311 Toxicity Characteristic Leaching Procedure (TCLP). To carry out TCLP for volatile organic analytes (VOA), such as benzene, in the Savannah River National Laboratory (SRNL) shielded cells (SC), a modified TCLP Zero-Headspace Extractor (ZHE) was developed. The modified method was demonstrated to be acceptable in a side by side comparison with an EPA recommended ZHE using nonradioactive saltstone containing tetraphenylborate (TPB). TCLP results for all saltstone samples tested containing TPB (both simulant and actual Tank 48H waste) were below the regulatory limit for benzene (0.5 mg/L). In general, higher curing temperatures corresponded to higher concentrations of benzene in TCLP extract. The TCLP performed on the simulant samples cured under the most extreme conditions (3000 mg/L TPB in salt and cured at 95 C for at least 144 days) resulted in benzene values that were greater than half the regulatory limit. Taking into account that benzene in TCLP extract was measured on the same order of …
Date: September 30, 2006
Creator: Crapse, K.; Cozzi, A.; Crawford, C. & Jurgensen, A.
Object Type: Report
System: The UNT Digital Library
Cyclone Boiler Field Testing of Advanced Layered NOx Control Technology in Sioux Unit 1 (open access)

Cyclone Boiler Field Testing of Advanced Layered NOx Control Technology in Sioux Unit 1

A four week testing program was completed during this project to assess the ability of the combination of deep staging, Rich Reagent Injection (RRI), and Selective Non-Catalytic Reduction (SNCR) to reduce NOx emissions below 0.15 lb/MBtu in a cyclone fired boiler. The host site for the tests was AmerenUE's Sioux Unit 1, a 500 MW cyclone fired boiler located near St. Louis, MO. Reaction Engineering International (REI) led the project team including AmerenUE, FuelTech Inc., and the Electric Power Research Institute (EPRI). This layered approach to NOx reduction is termed the Advanced Layered Technology Approach (ALTA). Installed RRI and SNCR port locations were guided by computational fluid dynamics (CFD) based modeling conducted by REI. During the parametric testing, NOx emissions of 0.12 lb/MBtu were achieved consistently from overfire air (OFA)-only baseline NOx emissions of 0.25 lb/MBtu or less, when firing the typical 80/20 fuel blend of Powder River Basin (PRB) and Illinois No.6 coals. From OFA-only baseline levels of 0.20 lb/MBtu, NOx emissions of 0.12 lb/MBtu were also achieved, but at significantly reduced urea flow rates. Under the deeply staged conditions that were tested, RRI performance was observed to degrade as higher blends of Illinois No.6 were used. NOx emissions …
Date: June 30, 2006
Creator: Cremer, Marc A. & Adams, Bradley R.
Object Type: Report
System: The UNT Digital Library
MERCURY vs. TART Comparisons to Verify Thermal Scattering (open access)

MERCURY vs. TART Comparisons to Verify Thermal Scattering

Recently the results from many Monte Carlo codes were compared for a series of theoretical pin-cells; the results are documented in ref. [3]; details are also provided here in Appendix A and B. The purpose of this earlier code comparison was primarily to determine how accurately our codes model both bound and free atom neutron thermal scattering. Prior to this study many people assumed that our Monte Carlo transport codes were all now so accurate that they would all produce more or less the same answers, say for example K-eff to within 0.1%. The results demonstrated that in reality we see a rather large spread in the results for even simple scalar parameters, such as K-eff, where we found differences in excess of 2%, far exceeding many people's expectations. The differences between code results were traced to four major factors, (1) Differences between the sets of nuclear data used. (2) The accuracy of nuclear data processing codes. (3) The accuracy of the models used in our Monte Carlo transport codes. (4) Code user selected input options. Naturally at Livermore we would like to insure that we minimize the effects of these factors. In this report we compare the results using …
Date: March 30, 2006
Creator: Cullen, D E; McKinley, S & Hagmann, C
Object Type: Report
System: The UNT Digital Library